Semiconductor processing systems having multiple plasma configurations

ABSTRACT

An exemplary system may include a chamber configured to contain a semiconductor substrate in a processing region of the chamber. The system may include a first remote plasma unit fluidly coupled with a first access of the chamber and configured to deliver a first precursor into the chamber through the first access. The system may still further include a second remote plasma unit fluidly coupled with a second access of the chamber and configured to deliver a second precursor into the chamber through the second access. The first and second access may be fluidly coupled with a mixing region of the chamber that is separate from and fluidly coupled with the processing region of the chamber. The mixing region may be configured to allow the first and second precursors to interact with each other externally from the processing region of the chamber.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/762,767, filed Feb. 8, 2013, entitled “Semiconductor ProcessingSystems Having Multiple Plasma Configurations.” The entire disclosure ofwhich is incorporated herein by reference for all purposes.

TECHNICAL FIELD

The present technology relates to semiconductor processes and equipment.More specifically, the present technology relates to processing systemshaving multiple plasma configurations.

BACKGROUND

Integrated circuits are made possible by processes which produceintricately patterned material layers on substrate surfaces. Producingpatterned material on a substrate requires controlled methods forremoval of exposed material. Chemical etching is used for a variety ofpurposes including transferring a pattern in photoresist into underlyinglayers, thinning layers, or thinning lateral dimensions of featuresalready present on the surface. Often it is desirable to have an etchprocess that etches one material faster than another facilitating, forexample, a pattern transfer process. Such an etch process is said to beselective to the first material. As a result of the diversity ofmaterials, circuits, and processes, etch processes have been developedwith a selectivity towards a variety of materials.

A wet HF etch preferentially removes silicon oxide over otherdielectrics and semiconductor materials. However, wet processes areunable to penetrate some constrained trenches and sometimes deform theremaining material. Dry etches produced in local plasmas formed withinthe substrate processing region can penetrate more constrained trenchesand exhibit less deformation of delicate remaining structures. However,local plasmas can damage the substrate through the production ofelectric arcs as they discharge.

Thus, there is a need for improved methods and systems for selectivelyetching materials and structures on semiconductor substrates that allowmore control over precursor chemistries and etch parameters. These andother needs are addressed by the present technology.

SUMMARY

Systems and methods are described relating to semiconductor processingchambers. An exemplary system may include a chamber configured tocontain a semiconductor substrate in a processing region of the chamber.The system may include a first remote plasma unit fluidly coupled with afirst access of the chamber and configured to deliver a first precursorinto the chamber through the first access. The system may still furtherinclude a second remote plasma unit fluidly coupled with a second accessof the chamber and configured to deliver a second precursor into thechamber through the second access. The first and second accesses may befluidly coupled with a mixing region of the chamber that is separatefrom and fluidly coupled with the processing region of the chamber. Themixing region may be configured to allow the first and second precursorsto interact with each other externally from the processing region of thechamber.

The system may further include a device positioned between the mixingregion and the processing region of the chamber. The device may beconfigured to at least partially suppress flow of ionic species directedtoward the processing region. The chamber may further include a gasdistribution assembly located within the chamber at a top portion of orabove the processing region of the chamber and configured to deliverboth the first and second precursors into the processing region of thechamber. The gas distribution assembly may include an upper plate and alower plate, and the plates may be coupled with one another to define avolume between the plates. The coupling of the plates may provide firstfluid channels through the upper and lower plates, and second fluidchannels through the lower plate that are configured to provide fluidaccess from the volume through the lower plate. The first fluid channelsmay be fluidly isolated from the volume between the plates and thesecond fluid channels. The volume defined may be fluidly accessiblethrough a side of the gas distribution assembly fluidly coupled with athird access in the chamber separate from the first and second accessesof the chamber.

The first access and the second access to the chamber may be coupledwith a top portion of the chamber. In embodiments the first access andsecond access may be separate from one another. The first and secondaccesses may also be coupled at a single location with a top portion ofthe chamber. The coupling of the first remote plasma unit and secondremote plasma unit with the single access may be configured to allow thefirst and second precursors to interact prior to accessing the mixingregion of the chamber. The first and second accesses may also be coupledwith a side portion of the chamber, and the accesses may be separatefrom one another or coupled together. The first access and second accessmay be fluidly coupled with a plenum radially distributed about thechamber and configured to provide access to the mixing region of thechamber at a plurality of locations throughout the plenum.

The chamber of the processing system may further include a showerheadpositioned between the mixing region and the processing region of thechamber that is configured to distribute the first and second precursorsthrough the chamber. The showerhead may define a plurality of aperturespositioned about an exterior portion of the showerhead. The showerheadmay include no apertures about an interior portion of the showerheadextending at least from a center point of the showerhead to about 25% ofa radial length of the showerhead.

The remote plasma units of the system may have the first remote plasmaunit including a first material and the second remote plasma unitincluding a second material. The first material may be selected based onthe composition of the first precursor, and the second material may beselected based on the composition of the second precursor. The firstmaterial and second material may be similar or different materials. Thefirst and second remote plasma units may be configured to operatebetween about 10 W to above or about 10 kW. The first remote plasma unitmay be configured to operate at a first power level that is selectedbased on the composition of the first precursor. The second remoteplasma unit may be configured to operate at a second power level that isselected based on the composition of the second precursor. The systemmay be configured to operate the first and second remote plasma units atpower levels that are similar or different from one another.

Methods are also described of operating a semiconductor processingsystem. The methods may include flowing a first precursor through afirst remote plasma unit into a semiconductor processing chamber. Themethods may also include flowing a second precursor through a secondremote plasma unit into the processing chamber. The first and secondprecursors may be combined in a mixing region of the chamber locatedfluidly upstream of a processing region of the chamber in which asubstrate resides. The first precursor may include a fluorine-containingprecursor, and the second precursor may include an oxygen-containingprecursor. The first precursor may be excited in the first remote plasmaunit at a first plasma power, and the second precursor may be excited inthe second remote plasma unit at a second plasma power. The first andsecond plasma powers may be similar or different from one another.

Such technology may provide numerous benefits over conventional systemsand techniques. For example, etch chemistries may be improved and tunedbased on the individual excitation of precursors. Additionally, greaterprocess uniformity may be provided based on the flow pathways that mayprovide more uniform gas mixtures. These and other embodiments, alongwith many of their advantages and features, are described in more detailin conjunction with the below description and attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the disclosedtechnology may be realized by reference to the remaining portions of thespecification and the drawings.

FIG. 1 shows a top plan view of one embodiment of an exemplaryprocessing tool.

FIG. 2A shows a schematic cross-sectional view of an exemplaryprocessing chamber.

FIG. 2B shows a detailed view of a portion of the processing chamberillustrated in FIG. 2A.

FIGS. 3A-3C show schematic views of exemplary showerhead configurationsaccording to the disclosed technology.

FIG. 4 shows an additional plan view of an exemplary showerheadaccording to the disclosed technology.

FIG. 5 shows a simplified cross-sectional view of a processing chamberaccording to the disclosed technology.

FIG. 6 shows a simplified cross-sectional view of a processing chamberaccording to the disclosed technology.

FIG. 7 shows a simplified cross-sectional view of a processing chamberaccording to the disclosed technology.

FIG. 8 shows a plan view of a cross-sectional portion of the processingchamber illustrated in FIG. 7 along line A-A.

FIG. 9 shows a simplified cross-sectional view of a processing chamberaccording to the disclosed technology.

FIG. 10 shows a plan view of a cross-sectional portion of the processingchamber illustrated in FIG. 9 along line B-B.

FIG. 11 shows a flowchart of a method of operating a semiconductorprocessing chamber according to the disclosed technology.

Several of the Figures are included as schematics. It is to beunderstood that the Figures are for illustrative purposes, and are notto be considered of scale unless specifically stated to be as such.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If only the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

DETAILED DESCRIPTION

The present technology includes systems for semiconductor processingthat provide improved fluid delivery mechanisms. Certain dry etchingtechniques include utilizing remote plasma systems to provide radicalfluid species into a processing chamber. Exemplary methods are describedin co-assigned patent application Ser. No. 13/439,079 filed on Apr. 4,2012, which is incorporated herein by reference to the extent notinconsistent with the claimed aspects and description herein. When dryetchant formulas are used that may include several radical species, theradical species produced from different fluids may interact differentlywith the remote plasma chamber. For example, precursor fluids foretching may include fluorine-containing precursors, and oxygen orhydrogen-containing precursors. The plasma cavity of the remote plasmasystem, as well as the distribution components to the processingchamber, may be coated or lined to provide protection from the reactiveradicals. For example, an aluminum plasma cavity may be coated with anoxide or nitride that will protect the cavity from fluorine radicals.However, if the precursors also contain hydrogen radicals, the hydrogenspecies may convert or reduce the aluminum oxide back to aluminum, atwhich point the fluorine may react directly with the aluminum producingunwanted byproducts such as aluminum fluoride.

Conventional technologies have dealt with these unwanted side effectsthrough regular maintenance and replacement of components, however, thepresent systems overcome this need by providing radical precursorsthrough separate fluid pathways into the processing chamber. Byutilizing two or more remote plasma systems each configured to deliverseparate precursor fluids, each system may be separately protected basedon the fluid being delivered. The inventors have also surprisinglydetermined that by providing the precursor species through separateremote plasma systems, the specific dissociation and plasmacharacteristics of each fluid can be tailored thereby providing improvedetching performance. Accordingly, the systems described herein provideimproved flexibility in terms of chemistry modulation. These and otherbenefits will be described in detail below.

Although the remaining disclosure will routinely identify specificetching processes utilizing the disclosed technology, it will be readilyunderstood that the systems and methods are equally applicable todeposition and cleaning processes as may occur in the describedchambers. Accordingly, the technology should not be considered to be solimited as to etching processes alone.

FIG. 1 shows a top plan view of one embodiment of a processing tool 100of deposition, etching, baking, and curing chambers according todisclosed embodiments. In the figure, a pair of front opening unifiedpods (FOUPs) 102 supply substrates of a variety of sizes that arereceived by robotic arms 104 and placed into a low pressure holding area106 before being placed into one of the substrate processing chambers108 a-f, positioned in tandem sections 109 a-c. A second robotic arm 110may be used to transport the substrate wafers from the holding area 106to the substrate processing chambers 108 a-f and back. Each substrateprocessing chamber 108 a-f, can be outfitted to perform a number ofsubstrate processing operations including the dry etch processesdescribed herein in addition to cyclical layer deposition (CLD), atomiclayer deposition (ALD), chemical vapor deposition (CVD), physical vapordeposition (PVD), etch, pre-clean, degas, orientation, and othersubstrate processes.

The substrate processing chambers 108 a-f may include one or more systemcomponents for depositing, annealing, curing and/or etching a dielectricfilm on the substrate wafer. In one configuration, two pairs of theprocessing chamber, e.g., 108 c-d and 108 e-f, may be used to depositdielectric material on the substrate, and the third pair of processingchambers, e.g., 1308 a-b, may be used to etch the deposited dielectric.In another configuration, all three pairs of chambers, e.g., 108 a-f,may be configured to etch a dielectric film on the substrate. Any one ormore of the processes described may be carried out in chamber(s)separated from the fabrication system shown in different embodiments. Itwill be appreciated that additional configurations of deposition,etching, annealing, and curing chambers for dielectric films arecontemplated by system 100.

FIG. 2A shows a cross-sectional view of an exemplary process chambersection 200 with partitioned plasma generation regions within theprocessing chamber. During film etching, e.g., titanium nitride,tantalum nitride, tungsten, silicon, polysilicon, silicon oxide, siliconnitride, silicon oxynitride, silicon oxycarbide, etc., a process gas maybe flowed into the first plasma region 215 through a gas inlet assembly205. One or more remote plasma system (RPS) units 201 may optionally beincluded in the system, and may process a first and second gas whichthen may travel through gas inlet assembly 205. The inlet assembly 205may include two or more distinct gas supply channels where the secondchannel (not shown) may bypass either of the RPS units 201, if included.Accordingly, in disclosed embodiments the precursor gases may bedelivered to the processing chamber in an unexcited state. In anotherexample, the first channel provided through the RPS may be used for theprocess gas and the second channel bypassing the RPS may be used for atreatment gas in disclosed embodiments. The process gases may be excitedwithin the RPS units 201 prior to entering the first plasma region 215.Accordingly, a fluorine-containing precursor as will be routinelyreferred below, for example, may pass through RPS 201 or bypass the RPSunits in disclosed embodiments. Various other examples encompassed bythis arrangement will be similarly understood.

A cooling plate 203, faceplate 217, ion suppressor 223, showerhead 225,and a substrate support 265, having a substrate 255 disposed thereon,are shown and may each be included according to disclosed embodiments.The pedestal 265 may have a heat exchange channel through which a heatexchange fluid flows to control the temperature of the substrate. Thisconfiguration may allow the substrate 255 temperature to be cooled orheated to maintain relatively low temperatures, such as between about−20° C. to about 200° C., or therebetween. The heat exchange fluid maycomprise ethylene glycol and/or water. The wafer support platter of thepedestal 265, which may comprise aluminum, ceramic, or a combinationthereof, may also be resistively heated in order to achieve relativelyhigh temperatures, such as from up to or about 100° C. to above or about1100° C., using an embedded resistive heater element. The heatingelement may be formed within the pedestal as one or more loops, and anouter portion of the heater element may run adjacent to a perimeter ofthe support platter, while an inner portion runs on the path of aconcentric circle having a smaller radius. The wiring to the heaterelement may pass through the stem of the pedestal 265, which may befurther configured to rotate.

The faceplate 217 may be pyramidal, conical, or of another similarstructure with a narrow top portion expanding to a wide bottom portion.The faceplate 217 may additionally be flat as shown and include aplurality of through-channels used to distribute process gases. Plasmagenerating gases and/or plasma excited species, depending on use of theRPS 201, may pass through a plurality of holes, shown in FIG. 2B, infaceplate 217 for a more uniform delivery into the first plasma region215.

Exemplary configurations may include having the gas inlet assembly 205open into a gas supply region 258 partitioned from the first plasmaregion 215 by faceplate 217 so that the gases/species flow through theholes in the faceplate 217 into the first plasma region 215. Structuraland operational features may be selected to prevent significant backflowof plasma from the first plasma region 215 back into the supply region258, gas inlet assembly 205, and fluid supply system (not shown). Thestructural features may include the selection of dimensions andcross-sectional geometries of the apertures in faceplate 217 todeactivate back-streaming plasma. The operational features may includemaintaining a pressure difference between the gas supply region 258 andfirst plasma region 215 that maintains a unidirectional flow of plasmathrough the showerhead 225. The faceplate 217, or a conductive topportion of the chamber, and showerhead 225 are shown with an insulatingring 220 located between the features, which allows an AC potential tobe applied to the faceplate 217 relative to showerhead 225 and/or ionsuppressor 223. The insulating ring 220 may be positioned between thefaceplate 217 and the showerhead 225 and/or ion suppressor 223 enablinga capacitively coupled plasma (CCP) to be formed in the first plasmaregion. A baffle (not shown) may additionally be located in the firstplasma region 215, or otherwise coupled with gas inlet assembly 205, toaffect the flow of fluid into the region through gas inlet assembly 205.

The ion suppressor 223 may comprise a plate or other geometry thatdefines a plurality of apertures throughout the structure that areconfigured to suppress the migration of ionically-charged species out ofthe plasma excitation region 215 while allowing uncharged neutral orradical species to pass through the ion suppressor 223 into an activatedgas delivery region between the suppressor and the showerhead. Indisclosed embodiments, the ion suppressor 223 may comprise a perforatedplate with a variety of aperture configurations. These uncharged speciesmay include highly reactive species that are transported with lessreactive carrier gas through the apertures. As noted above, themigration of ionic species through the holes may be reduced, and in someinstances completely suppressed. Controlling the amount of ionic speciespassing through the ion suppressor 223 may provide increased controlover the gas mixture brought into contact with the underlying wafersubstrate, which in turn may increase control of the deposition and/oretch characteristics of the gas mixture. For example, adjustments in theion concentration of the gas mixture can significantly alter its etchselectivity, e.g., TiNx:SiOx etch ratios, TiN:W etch ratios, etc. Inalternative embodiments in which deposition is performed, it can alsoshift the balance of conformal-to-flowable style depositions fordielectric materials.

The plurality of holes in the ion suppressor 223 may be configured tocontrol the passage of the activated gas, i.e., the ionic, radical,and/or neutral species, through the ion suppressor 223. For example, theaspect ratio of the holes, or the hole diameter to length, and/or thegeometry of the holes may be controlled so that the flow ofionically-charged species in the activated gas passing through the ionsuppressor 223 is reduced. The holes in the ion suppressor 223 mayinclude a tapered portion that faces the plasma excitation region 215,and a cylindrical portion that faces the showerhead 225. The cylindricalportion may be shaped and dimensioned to control the flow of ionicspecies passing to the showerhead 225. An adjustable electrical bias mayalso be applied to the ion suppressor 223 as an additional means tocontrol the flow of ionic species through the suppressor.

The ion suppression element 223 may function to reduce or eliminate theamount of ionically charged species traveling from the plasma generationregion to the substrate. Uncharged neutral and radical species may stillpass through the openings in the ion suppressor to react with thesubstrate. It should be noted that the complete elimination of ionicallycharged species in the reaction region surrounding the substrate is notalways the desired goal. In many instances, ionic species are requiredto reach the substrate in order to perform the etch and/or depositionprocess. In these instances, the ion suppressor may help to control theconcentration of ionic species in the reaction region at a level thatassists the process.

Showerhead 225 in combination with ion suppressor 223 may allow a plasmapresent in chamber plasma region 215 to avoid directly exciting gases insubstrate processing region 233, while still allowing excited species totravel from chamber plasma region 215 into substrate processing region233. In this way, the chamber may be configured to prevent the plasmafrom contacting a substrate 255 being etched. This may advantageouslyprotect a variety of intricate structures and films patterned on thesubstrate, which may be damaged, dislocated, or otherwise warped ifdirectly contacted by a generated plasma. Additionally, when plasma isallowed to contact the substrate or approach the substrate level, therate at which oxide species etch may increase. Accordingly, if theexposed second material is oxide, this material may be further protectedby maintaining the plasma remotely from the substrate.

The processing system may further include a power supply 240electrically coupled with the processing chamber to provide electricpower to the faceplate 217, ion suppressor 223, showerhead 225, and/orpedestal 265 to generate a plasma in the first plasma region 215 orprocessing region 233. The power supply may be configured to deliver anadjustable amount of power to the chamber depending on the processperformed. Such a configuration may allow for a tunable plasma to beused in the processes being performed. Unlike a remote plasma unit,which is often presented with on or off functionality, a tunable plasmamay be configured to deliver a specific amount of power to the plasmaregion 215. This in turn may allow development of particular plasmacharacteristics such that precursors may be dissociated in specific waysto enhance the etching profiles produced by these precursors.

A plasma may be ignited either in chamber plasma region 215 aboveshowerhead 225 or substrate processing region 233 below showerhead 225.A plasma may be present in chamber plasma region 215 to produce theradical-fluorine precursors from an inflow of the fluorine-containingprecursor. An AC voltage typically in the radio frequency (RF) range maybe applied between the conductive top portion of the processing chamber,such as faceplate 217, and showerhead 225 and/or ion suppressor 223 toignite a plasma in chamber plasma region 215 during deposition. An RFpower supply may generate a high RF frequency of 13.56 MHz but may alsogenerate other frequencies alone or in combination with the 13.56 MHzfrequency.

Plasma power can be of a variety of frequencies or a combination ofmultiple frequencies. In the exemplary processing system the plasma maybe provided by RF power delivered to faceplate 217 relative to ionsuppressor 223 and/or showerhead 225. The RF power may be between about10 watts and about 2000 watts, between about 100 watts and about 2000watts, between about 200 watts and about 1500 watts, or between about200 watts and about 1000 watts in different embodiments. The RFfrequency applied in the exemplary processing system may be low RFfrequencies less than about 200 kHz, high RF frequencies between about10 MHz and about 15 MHz, or microwave frequencies greater than or about1 GHz in different embodiments. The plasma power may becapacitively-coupled (CCP) or inductively-coupled (ICP) into the remoteplasma region.

The top plasma region 215 may be left at low or no power when a bottomplasma in the substrate processing region 233 is turned on to, forexample, cure a film or clean the interior surfaces bordering substrateprocessing region 233. A plasma in substrate processing region 233 maybe ignited by applying an AC voltage between showerhead 255 and thepedestal 265 or bottom of the chamber. A cleaning gas may be introducedinto substrate processing region 233 while the plasma is present.

A fluid, such as a precursor, for example a fluorine-containingprecursor, may be flowed into the processing region 233 by embodimentsof the showerhead described herein. Excited species derived from theprocess gas in the plasma region 215 may travel through apertures in theion suppressor 223, and/or showerhead 225 and react with an additionalprecursor flowing into the processing region 233 from a separate portionof the showerhead. Alternatively, if all precursor species are beingexcited in plasma region 215, no additional precursors may be flowedthrough the separate portion of the showerhead. Little or no plasma maybe present in the processing region 233. Excited derivatives of theprecursors may combine in the region above the substrate and, onoccasion, on the substrate to etch structures or remove species on thesubstrate in disclosed applications.

Exciting the fluids in the first plasma region 215 directly, or excitingthe fluids in the RPS units 201 a-b, may provide several benefits. Theconcentration of the excited species derived from the fluids may beincreased within the processing region 233 due to the plasma in thefirst plasma region 215. This increase may result from the location ofthe plasma in the first plasma region 215. The processing region 233 maybe located closer to the first plasma region 215 than the remote plasmasystem (RPS) 201, leaving less time for the excited species to leaveexcited states through collisions with other gas molecules, walls of thechamber, and surfaces of the showerhead.

The uniformity of the concentration of the excited species derived fromthe process gas may also be increased within the processing region 233.This may result from the shape of the first plasma region 215, which maybe more similar to the shape of the processing region 233. Excitedspecies created in the RPS units 201 a-b may travel greater distances inorder to pass through apertures near the edges of the showerhead 225relative to species that pass through apertures near the center of theshowerhead 225. The greater distance may result in a reduced excitationof the excited species and, for example, may result in a slower growthrate near the edge of a substrate. Exciting the fluids in the firstplasma region 215 may mitigate this variation for the fluid flowedthrough RPS 201.

The processing gases may be excited in the RPS units 201 a-b and may bepassed through the showerhead 225 to the processing region 233 in theexcited state. Alternatively, power may be applied to the firstprocessing region to either excite a plasma gas or enhance an alreadyexcited process gas from the RPS. While a plasma may be generated in theprocessing region 233, a plasma may alternatively not be generated inthe processing region. In one example, the only excitation of theprocessing gas or precursors may be from exciting the processing gasesin the RPS units 201 a-b to react with one another in the processingregion 233.

In addition to the fluid precursors, there may be other gases introducedat varied times for varied purposes, including carrier gases to aiddelivery. A treatment gas may be introduced to remove unwanted speciesfrom the chamber walls, the substrate, the deposited film and/or thefilm during deposition. A treatment gas may be excited in a plasma andthen used to reduce or remove residual content inside the chamber. Inother disclosed embodiments the treatment gas may be used without aplasma. When the treatment gas includes water vapor, the delivery may beachieved using a mass flow meter (MFM), an injection valve, or bycommercially available water vapor generators. The treatment gas may beintroduced to the processing region 233, either through the RPS unit orbypassing the RPS units, and may further be excited in the first plasmaregion.

FIG. 2B shows a detailed view of the features affecting the processinggas distribution through faceplate 217. As shown in FIGS. 2A and 2B,faceplate 217, cooling plate 203, and gas inlet assembly 205 intersectto define a gas supply region 258 into which process gases may bedelivered from gas inlet 205. The gases may fill the gas supply region258 and flow to first plasma region 215 through apertures 259 infaceplate 217. The apertures 259 may be configured to direct flow in asubstantially unidirectional manner such that process gases may flowinto processing region 233, but may be partially or fully prevented frombackflow into the gas supply region 258 after traversing the faceplate217.

The gas distribution assemblies such as showerhead 225 for use in theprocessing chamber section 200 may be referred to as dual channelshowerheads (DCSH) and are additionally detailed in the embodimentsdescribed in FIG. 2A as well as FIGS. 3A-C herein. The dual channelshowerhead may provide for etching processes that allow for separationof etchants outside of the processing region 233 to provide limitedinteraction with chamber components and each other prior to beingdelivered into the processing region.

The showerhead 225 may comprise an upper plate 214 and a lower plate216. The plates may be coupled with one another to define a volume 218between the plates. The coupling of the plates may be so as to providefirst fluid channels 219 through the upper and lower plates, and secondfluid channels 221 through the lower plate 216. The formed channels maybe configured to provide fluid access from the volume 218 through thelower plate 216 via second fluid channels 221 alone, and the first fluidchannels 219 may be fluidly isolated from the volume 218 between theplates and the second fluid channels 221. The volume 218 may be fluidlyaccessible through a side of the gas distribution assembly 225. Althoughthe exemplary system of FIG. 2 includes a dual-channel showerhead, it isunderstood that alternative distribution assemblies may be utilized thatmaintain first and second precursors fluidly isolated prior to theprocessing region 233. For example, a perforated plate and tubesunderneath the plate may be utilized, although other configurations mayoperate with reduced efficiency or not provide as uniform processing asthe dual-channel showerhead as described.

In the embodiment shown, showerhead 225 may distribute via first fluidchannels 219 process gases which contain plasma effluents uponexcitation by a plasma in chamber plasma region 215 or from RPS units201 a-b. In embodiments, the process gas introduced into the RPS units201 and/or chamber plasma region 215 may contain fluorine, e.g., CF₄,NF₃ or XeF₂, oxygen, e.g. N₂O, or hydrogen-containing precursors, e.g.H₂ or NH₃. One or both process gases may also include a carrier gas suchas helium, argon, nitrogen (N₂), etc. Plasma effluents may includeionized or neutral derivatives of the process gas and may also bereferred to herein as a radical-fluorine precursor referring to theatomic constituent of the process gas introduced.

An additional dual channel showerhead, as well as this processing systemand chamber, are more fully described in patent application Ser. No.13/251,714 filed on Oct. 3, 2011, which is hereby incorporated byreference for all purposes to the extent not inconsistent with theclaimed features and description herein.

The gas distribution assemblies 225 for use in the processing chambersection 200 are referred to as dual channel showerheads (DCSH) and aredetailed in the embodiments described in FIGS. 3A-3C herein. The dualchannel showerhead may allow for flowable deposition of a dielectricmaterial, and separation of precursor and processing fluids duringoperation. The showerhead may alternatively be utilized for etchingprocesses that allow for separation of etchants outside of the reactionzone to provide limited interaction with chamber components and eachother prior to being delivered into the processing region.

Referring generally to the showerheads in FIGS. 3A-3C, precursors may beintroduced into the processing region by first being introduced into aninternal showerhead volume defined in the showerhead 300 by a firstmanifold 320, or upper plate, and second manifold 325, or lower plate.The manifolds may be perforated plates that define a plurality ofapertures. The precursors in the internal showerhead volume, typicallyreferred to as the third precursors, may flow into the processing region233 via apertures 375 formed in the lower plate. This flow path may beisolated from the rest of the process gases in the chamber, and mayprovide for the precursors to be in an unreacted or substantiallyunreacted state until entry into the processing region 233 definedbetween the substrate 255 and a bottom of the lower plate 325. Once inthe processing region 233, the two precursors may react with each otherand the substrate. The third precursor may be introduced into theinternal showerhead volume defined in the showerhead 300 through a sidechannel formed in the showerhead, such as channel 322 as shown in theshowerhead embodiments herein. The first and second precursor gases maybe in a plasma state including radicals from the RPS units or from aplasma generated in the first plasma region. Additionally, a plasma maybe generated in the processing region.

FIG. 3A illustrates an upper perspective view of a gas distributionassembly 300. In usage, the gas distribution system 300 may have asubstantially horizontal orientation such that an axis of the gasapertures formed therethrough may be perpendicular or substantiallyperpendicular to the plane of the substrate support (see substratesupport 265 in FIG. 2). FIG. 3B illustrates a bottom perspective view ofthe gas distribution assembly 300. FIG. 3C is a bottom plan view of thegas distribution assembly 300.

Referring to FIGS. 3A-3C, the gas distribution assembly 300 generallyincludes the annular body 340, the upper plate 320, and the lower plate325. The annular body 340 may be a ring which has an inner annular walllocated at an inner diameter, an outer annular wall located at an outerdiameter, an upper surface 315, and a lower surface 310. The uppersurface 315 and lower surface 310 define the thickness of the annularbody 340. A conduit 350 may be formed in the annular body 340 and acooling fluid may be flowed within the channel that extends around thecircumference of the annular body 340. Alternatively, a heating element351 may be extended through the channel that is used to heat theshowerhead assembly. Annular body 340 may additionally define a channel322 through which an additional precursor may be delivered to theprocessing chamber.

The upper plate 320 may be a disk-shaped body, and may be coupled withthe annular body 340 at the first upper recess. The upper plate may havea diameter selected to mate with the diameter of the upper recess, andthe upper plate may comprise a plurality of first apertures 360 formedtherethrough. The first apertures 360 may extend beyond a bottom surfaceof the upper plate 320 thereby forming a number of raised cylindricalbodies (not shown). In between each raised cylindrical body may be agap. As seen in FIG. 3A, the first apertures 360 may be arranged in apolygonal pattern on the upper plate 320, such that an imaginary linedrawn through the centers of the outermost first apertures 360 define orsubstantially define a polygonal figure, which may be for example, asix-sided polygon.

The lower plate 325 may have a disk-shaped body having a number ofsecond apertures 365 and third apertures 375 formed therethrough, asespecially seen in FIG. 3C. The lower plate 325 may have multiplethicknesses, with the thickness of defined portions greater than thecentral thickness of the upper plate 320, and in disclosed embodimentsat least about twice the thickness of the upper plate 320. The lowerplate 325 may also have a diameter that mates with the diameter of theinner annular wall of the annular body 340 at the first lower recess.The second apertures 365 may be defined by the lower plate 325 ascylindrical bodies extending up to the upper plate 320. In this way,channels may be formed between the first and second apertures that arefluidly isolated from one another, and may be referred to as first fluidchannels. Additionally, the volume formed between the upper and lowerplates may be fluidly isolated from the channels formed between thefirst and second apertures. As such, a fluid flowing through the firstapertures 360 will flow through the second apertures 365 and a fluidwithin the internal volume between the plates will flow through thethird apertures 375, and the fluids will be fluidly isolated from oneanother until they exit the lower plate 325 through either the second orthird apertures. Third apertures 375 may be referred to as second fluidchannels, which extend from the internal volume through the bottom plate325. This separation may provide numerous benefits including preventinga radical precursor from contacting a second precursor prior to reachinga processing region. By preventing the interaction of the gases,reactions within the chamber may be minimized prior to the processingregion in which the reaction is desired.

The second apertures 365 may be arranged in a pattern that aligns withthe pattern of the first apertures 360 as described above. In oneembodiment, when the upper plate 320 and bottom plate 325 are positionedone on top of the other, the axes of the first apertures 360 and secondapertures 365 align. In disclosed embodiments, the upper and lowerplates may be coupled with one another or directly bonded together.Under either scenario, the coupling of the plates may occur such thatthe first and second apertures are aligned to form a channel through theupper and lower plates. The plurality of first apertures 360 and theplurality of second apertures 365 may have their respective axesparallel or substantially parallel to each other, for example, theapertures 360, 365 may be concentric. Alternatively, the plurality offirst apertures 360 and the plurality of second apertures 365 may havethe respective axis disposed at an angle from about 1° to about 30° fromone another. At the center of the bottom plate 325 there may or may notbe a second aperture 365.

FIG. 3C is a bottom view of a showerhead 325 for use with a processingchamber according to disclosed embodiments. Showerhead 325 correspondswith the showerhead shown in FIG. 2A. Through-holes 365, which show aview of first fluid channels 219, may have a plurality of shapes andconfigurations in order to control and affect the flow of precursorsthrough the showerhead 325. Small holes 375, which show a view of secondfluid channels 221, may be distributed substantially evenly over thesurface of the showerhead, even amongst the through-holes 365, which mayhelp to provide more even mixing of the precursors as they exit theshowerhead than other configurations.

An alternative arrangement for a showerhead or faceplate according todisclosed embodiments is shown in FIG. 4. As shown, the showerhead 400may comprise a perforated plate or manifold. The assembly of theshowerhead may be similar to the showerhead as shown in FIG. 3, or mayinclude a design configured specifically for distribution patterns ofprecursor gases. Showerhead 400 may include an annular frame 410positioned in various arrangements within an exemplary processingchamber, such as one or more arrangements as shown in FIGS. 2, 5, 6, 7,and/or 9. On or within the frame may be coupled a plate 420, which maybe similar in disclosed embodiments to plate 320 as previouslydescribed. The plate may have a disc shape and be seated on or withinthe frame 410. The plate may be of a variety of thicknesses, and mayinclude a plurality of apertures 465 defined within the plate. Anexemplary arrangement as shown in FIG. 4 may include a pattern aspreviously described with reference to the arrangement in FIG. 3, andmay include a series of rings of apertures in a geometric pattern, suchas a hexagon as shown. As would be understood, the pattern illustratedis exemplary and it is to be understood that a variety of patterns, holearrangements, and hole spacing are encompassed in the design.

Turning to FIG. 5 is shown a simplified schematic of processing system500 is shown according to the disclosed technology. The chamber ofsystem 500 may include any of the components as previously discussed,and may be configured to house a semiconductor substrate 555 in aprocessing region 533 of the chamber. The substrate 555 may be locatedon a pedestal 565 as shown. Processing chamber 500 may include tworemote plasma units or systems (RPS) 501 a-b. In disclosed embodiments,the chamber of system 500 may include any number of additional plasmaunits above the two illustrated based on the number of precursors beingutilized. A first RPS unit 501 a may be fluidly coupled with a firstaccess 505 of the chamber of system 500, and may be configured todeliver a first precursor into the chamber of system 500 through thefirst access 505. A second RPS unit 501 b may be fluidly coupled with asecond access 510 of the chamber of system 500, and may be configured todeliver a second precursor into the chamber through the second access510. An exemplary configuration may include the first access 505 and thesecond access 510 coupled with a top portion of the chamber. Theexemplary configuration may further couple the RPS units with theaccesses such that the first access 505 and second access 510 areseparate from one another.

First and second plasma units 501 a-b may be the same or differentplasma units. For example, either or both systems may be RF plasmasystems, CCP plasma chambers, ICP plasma chambers, magneticallygenerated plasma systems including toroidal plasma systems, microwaveplasma systems, etc., or any other system type capable of forming aplasma or otherwise exciting and/or dissociating molecules therein. Thefirst access 505 and second access 510 may be coupled with a portion ofthe chamber to provide access to a mixing region 511 of the processingchamber. The mixing region 511 may be separate from and fluidly coupledwith the processing region 533 of the chamber. The mixing region 511 mayfurther be configured to allow the first and second precursors tointeract with each other externally from the processing region 533 ofthe chamber. For example, a first precursor delivered through the firstRPS unit 501 a and a second precursor delivered through the second RPSunit 501 b may enter the mixing region 511 through the respective accesslocations and mix within the region to provide a more uniform dispersionof species across a profile of the gas mixture. The mixing region 511may be at least partially defined by a top of the chamber of system 500and a distribution device, such as a showerhead 509 below. Showerhead509 may be similar to the showerhead illustrated in FIG. 4 in disclosedembodiments. Showerhead 509 may include a plurality of channels orapertures 507 that may be positioned and/or shaped to affect thedistribution and/or residence time of the precursors in the mixingregion 511 before proceeding through the chamber. For example,recombination may be affected or controlled by adjusting the number ofapertures, size of the apertures, or configuration of apertures acrossthe showerhead 509. Spacer 504, such as a ring of dielectric materialmay be positioned between the top of the chamber and the showerhead 509to further define the mixing region 511. As illustrated, showerhead 509may be positioned between the mixing region 511 and the processingregion 533 of the chamber, and the showerhead 509 may be configured todistribute the first and second precursors through the chamber 500.

The chamber of system 500 may include one or more of a series ofcomponents that may optionally be included in disclosed embodiments. Anadditional faceplate or showerhead 513 may be positioned below theshowerhead 509 in order to further affect the distribution of theprecursors directed through the chamber. In disclosed embodiments, theprecursors that are at least partially mixed in mixing region 511 may bedirected through the chamber via one or more of the operating pressureof the system, the arrangement of the chamber components, and the flowprofile of the precursors. Showerhead 509 and faceplate 513 may beseparated by spacer 506, which may include a ring of material, such as adielectric material, metal, or other composition separating the twoshowerheads. Faceplate 513 may provide additional mixing anddistribution of precursors to further provide a uniform profile throughthe mixed precursors. Faceplate 513 may be of a similar shape ordimensioning as showerhead 509, and may again have similarcharacteristics as the showerhead illustrated in FIG. 4. In disclosedembodiments, faceplate 513 may be of a greater or lesser thickness thanshowerhead 509. Additionally, channels or apertures 508 in faceplate 513may be shaped in a similar fashion to apertures 507 defined inshowerhead 509. In disclosed embodiments some or all of the apertures508 may be differently shaped such as illustrated with a tapered portionextending outward toward the processing region 533.

An additional plate or device 523 may be disposed below the faceplate513. Plate 523 may include a similar design as showerhead 509, and mayhave a similar arrangement as the showerhead illustrated at FIG. 4, forexample. Spacer 510 may be positioned between the faceplate 513 andplate 523, and may include similar components as previously discussed,such as a dielectric material. Apertures 524 may be defined in plate523, and may be distributed and configured to affect the flow of ionicspecies through the plate 523. For example, the apertures 524 may beconfigured to at least partially suppress the flow of ionic speciesdirected toward the processing region 533. The apertures 524 may have avariety of shapes including channels as previously discussed, and mayinclude a tapered portion extending outward away from the processingregion 533 in disclosed embodiments.

The chamber of system 500 optionally may further include a gasdistribution assembly 525 within the chamber. The gas distributionassembly 525, which may be similar in aspects to the dual-channelshowerheads as previously described, may be located within the chamberat a top portion of the processing region 533, or above the processingregion 533. The gas distribution assembly 525 may be configured todeliver both the first and second precursors into the processing region533 of the chamber. Although the exemplary system of FIG. 5 includes adual-channel showerhead, it is understood that alternative distributionassemblies may be utilized that maintain a third precursor fluidlyisolated from the radical species from the first and second precursorsprior to the processing region 533. For example, a perforated plate andtubes underneath the plate may be utilized, although otherconfigurations may operate with reduced efficiency or not provide asuniform processing as the dual-channel showerhead as described. Byutilizing one of the disclosed designs, a third precursor may beintroduced into the processing region 533 that is not previously excitedby a plasma prior to entering the processing region 533. Although notshown, an additional spacer may be positioned between the plate 523 andthe showerhead 525, such as an annular spacer, to isolate the platesfrom one another. In embodiments in which a third precursor is notrequired, the gas distribution assembly 525 may have a design similar toany of the previously described components, and may includecharacteristics similar to the showerhead illustrated in FIG. 4.

The gas distribution assembly 525 may comprise an upper plate and alower plate as previously discussed. The plates may be coupled with oneanother to define a volume 527 between the plates. The coupling of theplates may be such as to provide first fluid channels 540 through theupper and lower plates, and second fluid channels 545 through the lowerplate. The formed channels may be configured to provide fluid accessfrom the volume 527 through the lower plate, and the first fluidchannels 540 may be fluidly isolated from the volume 527 between theplates and the second fluid channels 545. The volume 527 may be fluidlyaccessible through a side of the gas distribution assembly 525, such aschannel 322 as previously discussed. The channel may be coupled with athird access in the chamber separate from the first access 505 and thesecond access 510 of the chamber 500.

The plasma cavities of the RPS units 501 a-b, and any mechanicalcouplings leading to the chamber accesses 505, 510 may be made ofmaterials based on the first and second precursors selected to be flowedthrough the RPS units 501 a-b. For example, in certain etchingoperations, a fluorine-containing precursor, e.g., NF₃, may be flowedthrough either of the first and second RPS units, such as RPS unit 501a. When a plasma is formed in the RPS unit 501 a, the molecules maydissociate into radical ions. If the RPS unit 501 a is made of anunaltered aluminum, fluorine radicals may react with the cavity wallsforming byproducts such as aluminum fluoride. Accordingly, RPS unit 501a may be formed with a first material that may be for example aluminumoxide, aluminum nitride, or another material with which the firstprecursor does not interact. The material of the RPS unit 501 a may beselected based on the composition of the first precursor, and may bespecifically selected such that the precursor does not interact with thechamber components.

Similarly, the second RPS unit 501 b may be made of a second materialthat is selected based on the second precursor. In disclosedembodiments, the first and second material may be different materials.For example, if an oxygen-containing precursor, such as N₂O or O₂, or ahydrogen containing precursor is flowed through the second RPS 501 b anda plasma is formed, dissociated radicals that may include O*, NO*, H*,etc., may interact with the plasma cavity of the RPS 501 b. If thechamber is similarly made of aluminum oxide, for example, hydrogenradicals in an exemplary embodiment may interact with the oxide, and mayremove the protective coating. Accordingly, RPS unit 501 b may be madeof a second material different from the first such as aluminum, oranother material with which the second precursor does not interact. Thismay be extended to the couplings or various other components of thechamber as well. Such coatings or materials selections may improveequipment degradation over time. Accordingly, for example, thecouplings, spacers, gas distribution assembly plates, etc. may eachinclude multiple plates made of one or more materials. Moreover, thechamber may not include one or more of the components previouslydescribed. For example, gas distribution assembly 525 may be removed inconfigurations that my not require a third precursor that is maintainedisolated from plasma species. Similarly, showerhead 509 may be removedin disclosed embodiments in which faceplate 513 may provide adequatedistribution profiles of the precursors.

In operation, one or both of the RPS units 501 a-b may be used toproduce a plasma within the unit to at least partially ionize the firstand/or second precursor. In one example in which a fluorine-containingprecursor and an oxygen-containing precursor are utilized, theoxygen-containing precursor may be flowed through the first RPS unit 501a and the fluorine-containing precursor may be flowed through the secondRPS unit 501 b. Such a configuration may be configured based on thetravel distances for the radical species. Although shown equal distancesfrom the processing chamber of system 500, based on the size andconfiguration of the RPS units 501, one or both of them may be furtherremoved from the chamber, such that the produced radical species mayhave a longer flow path to the chamber. For example, in an embodiment inwhich a hydrogen-containing precursor is used, because hydrogen radicalsmay recombine more quickly than fluorine radicals due to a shorterhalf-life, the hydrogen-containing precursor may be flowed through thechamber with the shorter flow path. However, it is to be understood thata variety of configurations may be utilized which may flow any or eitherprecursors through any or either RPS unit. Also, additional RPS unitsmay be utilized if additional precursors are to be utilized for theoperations to be performed.

The RPS units 501 a-b may be operated at power levels from between belowor about 10 W up to above or about 10 or 15 kW in various embodiments.The inventors have advantageously determined that an additional benefitof the disclosed technology is that the power and plasma profile of eachRPS unit may be tuned to the particular precursor used. In this way,each plasma may have separate plasma potentials within each RPS unit.For example, continuing the example with a fluorine-containing precursorand an oxygen or hydrogen-containing precursor, some conventionalsystems require that both precursors requiring dissociation be flowedthrough the same RPS unit. In addition to the potential deterioration ofthe plasma cavity and RPS unit as discussed above, a plasma profilebeneficial to both precursors may not be available. Continuing theexample, fluorine-containing precursors including NF₃ may be processedat a relatively low level of power in the RPS unit. By operating the RPSat a power level at or below 100 W, 200 W, 400 W, up to 1000 W or more,the precursor may be dissociated to a lesser degree that does notcompletely ionize the particles, and includes independent radicalsincluding NF and NF₂ species as well. Additionally, the RPS unitprocessing the oxygen or hydrogen-containing precursor may be operatedat a much higher power level as complete dissociation may be desired.Accordingly, the RPS unit may be operated between up to or above about1000 W and up to or above about 10 kW or more. The RF frequency appliedin the exemplary processing system may be low RF frequencies less thanabout 500 kHz, high RF frequencies between about 10 MHz and about 15 MHzor microwave frequencies greater than or about 1 GHz in differentembodiments. As such, the first RPS unit 501 a may be configured tooperate at a first power level that is selected based on the compositionof the first precursor, and the second RPS may be configured to operateat a second power level that is selected based on the composition of thesecond precursor. The two RPS units 501 a-b may be configured to operateat power levels different from one another. Such a configuration mayrequire separate or decoupled power sources, among other changes.

A further advantage of the present configuration may be based on theflow rates of the respective precursors. Initially, as previouslydiscussed, either or both of the first and second precursors may beflowed with one or more carrier gases. However, the amount of eachprecursor utilized in exemplary operations may not be similar, which maydetrimentally affect conventional systems including a single RPS unit.For example, if the first and second precursors are flowed through asingle RPS unit, increasing the flow of one precursor may require anincrease in the flow of the second precursor to ensure that an adequateamount of radical species are produced of each species. This may occurdue to the dilution of either of the respective precursors from theincrease in amount of the other precursor. In the present technology,however, such an issue may be overcome based on the separately ionizedprecursors. Accordingly, further process tuning may be provided byallowing individual modulation of precursor flows, while still providingadequate radical species of other precursor sources.

Additional flexibility may be provided by operating one of the RPS unitsbut not the other. For example, a fluorine-containing precursor may beflowed through the first RPS unit 501 a that is configured to operate ata power level that may be lower based on the precursor. An oxygen orhydrogen-containing precursor may be flowed through the second RPS unit501 b in which a plasma is not formed such that the molecular precursorflows to the mixing region 511. When the first and second precursorsseparately enter the mixing region 511 they may interact, and the firstprecursor that has been at least partially radicalized in RPS unit 501 amay ionize a portion of the second precursor, in which case powerefficiency of the system may be improved. Based on these examples, it isunderstood that many aspects may be reversed or changed in disclosedembodiments of the technology based on various operationalcharacteristics.

Additionally, a plasma as described earlier may be formed in a region ofthe chamber defined between two or more of the components previouslydiscussed. By providing an additional plasma source, such as a CCPsource, the plasma particles produced in the RPS units may be continuedor enhanced, and the rate of recombination may be further tuned. Forexample, a plasma region such as a first plasma region 515 as previouslydescribed, may be formed between faceplate 508 and plate 523. Spacer 510may maintain the two devices electrically isolated from one another inorder to allow a plasma field to be formed. Faceplate 508 may beelectrically charged while plate 523 may be grounded or DC biased toproduce a plasma field within the region defined between the plates. Theplates may additionally be coated or seasoned in order to minimize thedegradation of the components between which the plasma may be formed.The plates may additionally include compositions that may be less likelyto degrade or be affected including ceramics, metal oxides, etc.

Operating a conventional CCP plasma may degrade the chamber components,which may remove particles that may be inadvertently distributed on asubstrate. Such particles may affect performance of devices formed fromthese substrates due to the metal particles that may provideshort-circuiting across semiconductor substrates. However, the CCPplasma of the disclosed technology may be operated at reduced orsubstantially reduced power because the CCP plasma may be utilized onlyto maintain the plasma, and not to ionize species within the plasmaregion. For example, the CCP plasma may be operated at a power levelbelow or about 1 kW, 500 W, 250 W, 100 W, 50 W, 20 W, etc. or less.Moreover, the CCP plasma may produce a flat plasma profile which mayprovide a uniform plasma distribution within the space. As such, a moreuniform plasma may be delivered downstream to the processing region ofthe chamber.

FIG. 6 shows a simplified cross-sectional view of a processing system600 according to the disclosed technology. The processing chamber ofsystem 600 may include some or all of the components previouslydescribed with respect to the processing chamber of FIG. 5. For example,the processing chamber may be configured to house a semiconductorsubstrate 655 in a processing region 633 of the chamber. The substrate655 may be located on a pedestal 665 as shown. The system 600 mayinclude two or more remote plasma units or systems (RPS) 601 a-b. Thesystem 600 may include a first RPS unit 601 a and a second RPS unit 601b as previously discussed, which may be configured to provideradicalized precursors to the processing chamber. As illustrated in theFigure, the first and second RPS units may be fluidly coupled to thechamber in such a way as to couple with a single access to the chamber.Accordingly, in disclosed embodiments the first and second accesses arecoupled at a single location 605 that may be positioned along the topsurface of the processing chamber. The coupling of the first RPS unit601 a and the second RPS unit 601 b with the single access 605 may beconfigured to allow a first and second precursor to interact prior toaccessing the mixing region 611 of the chamber.

The components coupling the RPS units 601 to the chamber may includepiping 614 in several arrangements. For example, the piping may bearranged in a Y-connection as illustrated in the Figure, or for examplein a T-connection as illustrated in FIG. 2. Various other arrangementsand connections may similarly be used to couple the RPS units 601. Thepiping 614 may be coated or produced of materials designed to havelittle or no interaction with the precursors that may be flowed throughthe RPS units. The piping 614 may be formed with rifling, knurling, orother designs configured to provide turbulence and mixing of theprecursors prior to entering the chamber. The separately excitedprecursors may interact above the access 605 to provide additionalmixing that may provide improved uniformity of distribution of theprecursors through the chamber. The access 605 may be formed in a topplate such as a faceplate 603 that at least partially defines a mixingregion 611. The mixing region may be additionally defined by a plate 623that may be configured to suppress the flow of ionic species into theprocessing region 633.

Plate 623 may include a similar design and may have a similararrangement as the showerhead illustrated at FIG. 4, for example. Spacer610 may be positioned between the faceplate 603 and plate 623, and mayinclude similar components as previously discussed, such as a dielectricmaterial. Apertures 624 may be defined in plate 623, and may bedistributed and configured to affect the flow of ionic species throughthe plate 623. For example, the apertures 624 may be configured to atleast partially suppress the flow of ionic species directed toward theprocessing region 633. The apertures 624 may have a variety of shapesincluding channels as previously discussed, and may include a taperedportion extending upward away from the processing region 633 indisclosed embodiments.

System 600 may further include a gas distribution assembly 625 withinthe chamber. The gas distribution assembly 625, which may be similar inaspects to the dual-channel showerheads as previously described, may belocated within the chamber at a top portion of the processing region633, or above the processing region 633. The gas distribution assembly625 may be configured to deliver both the first and second precursorsinto the processing region 633 of the chamber. Although the exemplarysystem of FIG. 6 includes a dual-channel showerhead, it is understoodthat alternative distribution assemblies may be utilized that maintain athird precursor fluidly isolated from the radical species of the firstand second precursors prior to entering the processing region 633.Although not shown, an additional spacer may be positioned between theassembly 623 and the showerhead 625, such as an annular spacer, toisolate the plates from one another. In embodiments in which a thirdprecursor is not required, the gas distribution assembly 625 may have adesign similar to any of the previously described components, and mayinclude characteristics similar to the showerhead illustrated in FIG. 4.

The gas distribution assembly 625 may comprise an upper plate and alower plate as previously discussed. The plates may be coupled with oneanother to define a volume 627 between the plates. The coupling of theplates may be such as to provide first fluid channels 640 through theupper and lower plates, and second fluid channels 645 through the lowerplate. The formed channels may be configured to provide fluid accessfrom the volume 627 through the lower plate, and the first fluidchannels 640 may be fluidly isolated from the volume 627 between theplates and the second fluid channels 645. The volume 627 may be fluidlyaccessible through a side of the gas distribution assembly 625, such aschannel 322 as previously discussed. The channel may be coupled with athird access in the chamber separate from the first access 605 of thechamber 600.

A plasma as described earlier may be formed in a region of the chamberdefined between two or more of the components previously discussed. Byproviding an additional plasma source, such as a CCP source, the plasmaeffluents may be further tuned as previously described. For example, aplasma region such as a first plasma region 615 as previously described,may be formed in the mixing region 611 between faceplate 603 andassembly 623. Spacer 610 may maintain the two devices electricallyisolated from one another in order to allow a plasma field to be formed.Faceplate 603 may be electrically charged while assembly 623 may begrounded or DC biased to produce a plasma field within the regiondefined between the plates. The plates may additionally be coated orseasoned in order to minimize the degradation of the components betweenwhich the plasma may be formed. The plates may additionally includecompositions that may be less likely to degrade or be affected includingceramics, metal oxides, etc.

By producing a plasma within the mixing region 611, plasma effluentsfrom the CCP may backflow through the access 605 and travel back throughpiping 614, which may degrade the components. Accordingly, a blocker602, such as a mesh screen or device configured to suppress back-flowingplasma, may be incorporated into piping 614 or access 605 to protectupstream components such as the RPS units 601 and piping 614.

In disclosed embodiments, the system 600 chamber may also not includeCCP plasma capabilities, and plasma production may be made, for example,exclusively from the RPS units 601 a-b. Producing CCP plasma often maydegrade the portions of a chamber in which the plasma is formed, whichmay cause metal or other material sputtering from the chamber surfaces.The particles displaced from the chamber may pass through the chamberregions and deposit or interact with a substrate on which a processingoperation is being performed. In this way, the finally producedsubstrate may have performance issues such as short circuit occurrencesdue to the inclusion of displaced metallic, conductive, or othermaterials from the chamber surfaces.

FIG. 7 shows a simplified cross-sectional view of a processing chambersystem 700 according to the disclosed technology. Processing system 700may include some or all of the components previously described withrespect to the processing systems 500 and/or 600 of FIGS. 5 and 6. Forexample, processing system 700 may be configured to house asemiconductor substrate 755 in a processing region 733 of the chamber.The substrate 755 may be located on a pedestal 765 as shown. Processingsystem 700 may include two or more remote plasma units or systems (RPS)701 a-b. The system may include a first RPS unit 701 a and a second RPSunit 701 b as previously discussed, which may be configured to provideradicalized precursors to the processing chamber.

As illustrated in the Figure, the first and second RPS units may befluidly coupled with a side portion of the chamber. The first access 705and second accesses 710 may be disposed separately from one another. Thefirst access 705 and second access 710 may be fluidly coupled with aplenum 712 radially distributed about the chamber. The plenum 712 may becoupled about the circumference of the chamber, and may be configured toprovide access to the mixing region 711 of the chamber at a plurality oflocations throughout the plenum 712. The plenum 712 may also be locatedwithin the confines of the chamber housing, but may have an annularshape at least partially defining the mixing region 711. The pluralityof locations throughout the plenum 712 by which access is provided tothe mixing region 711 may include ports or apertures 714 defined aboutan interior portion of the plenum 712. The ports 714 may be positionedor configured to provide a more uniform delivery of the precursors intothe mixing region 711 from the plenum 712. In disclosed embodiments, theinner wall of the plenum 712 may define 2 or more ports 714, and maydefine greater than or about 4 ports, 6, 7, 8, 9, 10, 12, 15, 20, 25,30, 40, 50, etc. or more ports 714 defined about the plenum 712.

In disclosed embodiments the first access 705 and second access 710 maybe coupled prior to their accessing the plenum 712, such as with acoupling or piping as previously described. Accordingly, in disclosedembodiments the first and second accesses are coupled at a singlelocation that may be positioned along the top surface of the processingchamber or along a side portion of the chamber housing. The coupling ofthe first RPS unit 701 a and the second RPS unit 701 b with a singleaccess may be configured to allow the a first and second precursors tointeract prior to accessing the plenum 712 and mixing region 711 of thechamber.

The separately excited precursors may interact about the plenum 712 toprovide additional mixing that may provide improved uniformity ofdistribution of the precursors through the chamber. As discussed, theplenum may at least partially define the mixing region 711 that may befurther defined in part by a top plate such as a faceplate 703. Themixing region may be additionally defined by an plate 723 that may beconfigured to suppress the flow of ionic species into the processingregion 733.

Plate 723 may include a similar design and may have a similararrangement as the showerhead illustrated at FIG. 4, for example. Thehousing of plenum 712 may formed or coated with a dielectric materialthat may allow the faceplate 703 and plate 723 to be electricallyisolated from one another as described further below. Apertures 724 maybe defined in plate 723, and may be distributed and configured to affectthe flow of ionic species through the plate 723. For example, theapertures 724 may be configured to at least partially suppress the flowof ionic species directed toward the processing region 733. Theapertures 724 may have a variety of shapes including channels aspreviously discussed, and may include a tapered portion as illustratedextending upward away from the processing region 733 in disclosedembodiments.

System 700 may further include a gas distribution assembly 725 withinthe chamber. The gas distribution assembly 725, which may be similar inaspects to the dual-channel showerheads as previously described, may belocated within the system 700 chamber at a top portion of the processingregion 733, or above the processing region 733. The gas distributionassembly 725 may be configured to deliver both the first and secondprecursors into the processing region 733 of the chamber. Although theexemplary system of FIG. 7 includes a dual-channel showerhead, it isunderstood that alternative distribution assemblies may be utilized thatmaintain a third precursor fluidly isolated from the radical species ofthe first and second precursors prior to entering the processing region733. Although not shown, an additional spacer may be positioned betweenthe plate 723 and the showerhead 725, such as an annular spacer, toisolate the plates from one another. In embodiments in which a thirdprecursor is not required, the gas distribution assembly 725 may have adesign similar to any of the previously described components, and mayinclude characteristics similar to the showerhead illustrated in FIG. 4.

The gas distribution assembly 725 may comprise an upper plate and alower plate as previously discussed. The plates may be coupled with oneanother to define a volume 727 between the plates. The coupling of theplates may be such as to provide first fluid channels 740 through theupper and lower plates, and second fluid channels 745 through the lowerplate. The formed channels may be configured to provide fluid accessfrom the volume 727 through the lower plate, and the first fluidchannels 740 may be fluidly isolated from the volume 727 between theplates and the second fluid channels 745. The volume 727 may be fluidlyaccessible through a side of the gas distribution assembly 725, such aschannel 322 as previously discussed. The channel may be coupled with athird access in the chamber separate from the first access 705 of thesystem 700 chamber.

A plasma as described earlier may be formed in a region of the system700 chamber defined between two or more of the components previouslydiscussed. By providing an additional plasma source, such as a CCPsource, the plasma effluents may be further tuned as previouslydescribed. For example, a plasma region such as a first plasma region715 as previously described, may be formed in the mixing region 711between faceplate 703 and plate 723. As discussed, the housing of plenum712 may maintain the two devices electrically isolated from one anotherin order to allow a plasma field to be formed. Faceplate 703 may beelectrically charged while plate 723 may be grounded or DC biased toproduce a plasma field within the region defined between the plates. Theplates may additionally be coated or seasoned in order to minimize thedegradation of the components between which the plasma may be formed.The plates may additionally include compositions that may be less likelyto degrade or be affected including ceramics, metal oxides, etc.

FIG. 8 shows a top plan view of a cross-sectional portion of the system700 chamber illustrated in FIG. 7 along line A-A. As previouslydescribed, plenum 812 may be defined by a housing including an outerwall 802 and an inner wall 804. The housing may be a contiguousmaterial, or may be two separate materials comprising the inner wall 804and outer wall 802. Access may be provided to the plenum 812 via anynumber of access points that may include first access 805 and secondaccess 810. For example, a single access to the plenum may be providedby which two or more RPS units may deliver plasma effluents to theprocessing chamber. As illustrated, first access 805 may define one ormore spaces 806 to provide access about the plenum space 812. Asillustrated, two spaces 806 a and 806 b are shown providing access inmultiple directions from the first access 805. In disclosed embodimentsthe first access 805 may include fewer or more spaces 806 by which afirst precursor may be delivered to the plenum. For example, a singlespace 806 a may be defined to allow ingress to the plenum 805 from asingle position. Additionally, although illustrated as being defined tothe outer wall 802, first access 805 may, for example, be of a smallerradius than the distance between the inner wall 802 and outer wall 804defining plenum 812. Accordingly, an additional space 806 may beprovided that is directed towards the outer wall 802 (not shown) fromthe first access 805. Moreover, although illustrated as extending intoplenum 812 to provide additional flow control over the deliveredprecursor, first access 805 may include access at the top portion of theplenum 812 such that the precursor may simply flow down and outwardthrough the plenum 812 with an undirected current flow.

A similar configuration may be provided with second access 810 by whicha second precursor may be delivered to the chamber through plenum 812.Second access 810 may include one or more spaces 813 that provide accessto the plenum space 812. As illustrated, two spaces 813 a and 813 b areshown providing access in multiple directions from the second access810. Similar modifications may be provided as discussed above withrespect to first access 805. In an exemplary configuration in which asingle space is provided from each of first access 805 and second access810, the spaces may be provided in similar or in opposite directions.For example, if space 806 a is defined by first access 805 to direct theprecursor in one direction about the plenum 812, space 813 b may bedefined by second access 810 to direct the second precursor in anopposite direction about plenum 812. Various alternatives as would beunderstood are similarly encompassed. Additionally, as discussed withrespect to first access 805, second access 810 may port only to the topof the plenum housing such that no further direction is provided to theprecursor as it is delivered to the plenum 812, and the precursor mayflow naturally about the plenum 812.

Inner wall 804 of plenum 812 may at least partially define mixing region811 as previously described. Ports or apertures 814 may be definedthroughout the distance around inner wall 804 to provide access by whichthe precursors may enter the mixing region 811, prior to traversingassembly 823 via ports 824. Ports 814, such as port 814 x, may bedefined in a variety of ways along inner wall 804, and may have straightlumen-style characteristics as shown, or may be angled toward mixingregion 811 or away from mixing region 811 in disclosed embodiments toprovide further ways by which the distribution of the precursors may becontrolled or tuned. As shown, ports 814 a and 814 b are illustratedproximate to the first access 805 and second access 810 respectively. Indisclosed embodiments, these ports may be included or not included tofurther affect the distribution of precursors into the mixing region811. Additional ports 814 may also be removed at structured or varyingintervals, in which case the inner wall 804 remains continuous along thesection in which a port 814 is not defined. Once delivered precursorsare directed or allowed to flow along plenum 812 and through ports 814,the precursors may interact and further mix in mixing region 811. Theprecursor mixture may then flow through apertures 824 through assembly823 toward the processing region in which the precursors may, forexample, be used to perform an etch process on a substrate.

FIG. 9 shows a simplified cross-sectional view of a processing chamberaccording to the disclosed technology. Processing chamber system 900 mayinclude some or all of the components previously described with respectto the systems described with respect to any of FIG. 5, 6, or 7. Forexample, the system 900 chamber may be configured to house asemiconductor substrate 955 in a processing region 933 of the chamber.The substrate 955 may be located on a pedestal 965 as shown. Theprocessing chamber of system 900 may include two or more remote plasmaunits or systems (RPS) 901 a-b. The chamber may include a first RPS unit901 a and a second RPS unit 901 b as previously discussed, which may beconfigured to provide radicalized precursors to the processing chamber.A first RPS unit 901 a may be fluidly coupled with a first access 905 ofthe chamber, and may be configured to deliver a first precursor into thechamber through the first access 905. A second RPS unit 901 b may befluidly coupled with a second access 910 of the chamber, and may beconfigured to deliver a second precursor into the chamber through thesecond access 910. An exemplary configuration may include the firstaccess 905 and the second access 910 coupled with a top portion of thechamber. The exemplary configuration may further couple the RPS unitswith the accesses such that the first access 905 and second access 910are separate from one another.

The separately excited precursors produced in the RPS units 901 may bedirected or otherwise flowed in mixing region 911 in which theprecursors may mix to provide improved uniformity of distribution of theprecursors through the chamber. The accesses 905, 910 may be formed in atop plate such as a faceplate 903 that at least partially defines themixing region 911. The mixing region may be additionally defined by ashowerhead or configuration of portions 909, 914 that may be utilized todistribute the precursors through the chamber. Spacer 908 mayadditionally define a portion of the mixing region 911.

The showerhead including portions 909, 914 may include one, two, or moreplates or components configured to affect the distribution ofprecursors. As illustrated, component 909 may comprise an annular platecoupled with a plate structure 914 disposed below the annular plate 909.In disclosed embodiments, plate 914 may be disposed in line with annularplate 909. Annular plate 909 and plate 914 may be composed of similar ordifferent materials in disclosed embodiments. For example, annularportion 909 may be formed of a dielectric material or othernon-conducting material while plate 914 may comprise a metal or otherconducting portion that may act as an electrode as discussed below. Asanother example, both portions 909, 914 may comprise a conductive metal,and spacers 908, 912 may electrically isolate the plate from otherportions of the system 900 chamber. Apertures 907 may be defined inannular portion 909 through which the mixed precursors may be flowed.

A plate 923 that may be positioned below the showerhead includingportions 909, 914, and may be configured to suppress the flow of ionicspecies into the processing region 933. Plate 923 may include a similardesign and may have a similar arrangement as the showerhead illustratedat FIG. 4, for example. Spacer 912 may be positioned between theshowerhead including portions 909, 914 and plate 923, and may includesimilar components as previously discussed, such as a dielectricmaterial. Apertures 924 may be defined in plate 923, and may bedistributed and configured to affect the flow of ionic species throughthe plate 923. For example, the apertures 924 may be configured to atleast partially suppress the flow of ionic species directed toward theprocessing region 933. The apertures 924 may have a variety of shapesincluding channels as previously discussed, and may include a taperedportion extending upward away from the processing region 933 indisclosed embodiments. As illustrated, a region 915 may be defined atleast partially by the showerhead including portions 909, 914 and plate923. This region may allow for additional mixing of the precursors orprocessing of the precursors as discussed below.

The chamber of system 900 may further include a gas distributionassembly 925 within the chamber. The gas distribution assembly 925,which may be similar in aspects to the dual-channel showerheads aspreviously described, may be located within the system 900 chamber at atop portion of the processing region 933, or above the processing region933. The gas distribution assembly 925 may be configured to deliver boththe first and second precursors into the processing region 933 of thechamber 900. Although the exemplary system of FIG. 9 includes adual-channel showerhead, it is understood that alternative distributionassemblies may be utilized that maintain a third precursor fluidlyisolated from the radical species of the first and second precursorsprior to entering the processing region 933. Although not shown, anadditional spacer may be positioned between the assembly 923 and theshowerhead 925, such as an annular spacer, to isolate the plates fromone another. In embodiments in which a third precursor is not required,the gas distribution assembly 925 may have a design similar to any ofthe previously described components, and may include characteristicssimilar to the showerhead illustrated in FIG. 4.

The gas distribution assembly 925 may comprise an upper plate and alower plate as previously discussed. The plates may be coupled with oneanother to define a volume 927 between the plates. The coupling of theplates may be such as to provide first fluid channels 940 through theupper and lower plates, and second fluid channels 945 through the lowerplate. The formed channels may be configured to provide fluid accessfrom the volume 927 through the lower plate, and the first fluidchannels 940 may be fluidly isolated from the volume 927 between theplates and the second fluid channels 945. The volume 927 may be fluidlyaccessible through a side of the gas distribution assembly 925, such aschannel 322 as previously discussed. The channel may be coupled with athird access in the chamber separate from the first access 905 andsecond access 910 of the system 900 chamber.

A plasma as described earlier may be formed in a region of the system900 chamber defined between two or more of the components previouslydiscussed. By providing an additional plasma source, such as a CCPsource, the plasma effluents may be further tuned as previouslydescribed. For example, a plasma region 915, which may be similar incertain aspects to first plasma region 215 as previously described, maybe formed in the area defined between the showerhead including portions909, 914 and plate 923. Spacer 912 may maintain the two deviceselectrically isolated from one another in order to allow a plasma fieldto be formed. In disclosed embodiments, portion 914 of the showerheadmay be electrically charged and isolated by portion 909 as previouslydiscussed which may be electrically insulating, for example. Theshowerhead may be electrically charged partially or entirely, whileplate 923 may be grounded or DC biased to produce a plasma field withinthe region defined between the plates. The plates may additionally becoated or seasoned in order to minimize the degradation of thecomponents between which the plasma may be formed. The plates mayadditionally include compositions that may be less likely to degrade orbe affected including ceramics, metal oxides, etc.

FIG. 10 shows a top plan view of a cross-sectional portion of theprocessing chamber illustrated in FIG. 9 along line B-B. The showerhead1000 including portions 1009 and 1014 may include one or more plates orcomponents as previously discussed. Portion 1009 may include an exteriorannular portion of the showerhead that surrounds an interior portion1014 of the showerhead 1000. The portion 1014 may be contained withinthe plane of the exterior portion 1009, or may be disposed or seatedabove or below the exterior portion 1009. The interior portion may bewelded or otherwise mechanically coupled with or to the exterior portionto form the showerhead 1000. Exterior portion 1009 may include a section1016 that may be an annular inner portion of the exterior portion 1009of the showerhead 1000. Section 1016 may be an additional annularsection coupled with both exterior portion 1009 and interior portion1014. Section 1016 may include a plurality of apertures 1007 definedwithin section 1016 that provide access through showerhead 1000. Theapertures 1007 may be defined in a variety of patterns, such as a ringpattern as illustrated. The showerhead 1000 may or may not includeapertures in the interior portion 1014 in disclosed embodiments. Forexample, interior portion 1014 may be devoid of apertures, and aperturesmay not be formed in a region extending from a center point of theshowerhead 1000. Based on the radial length of the showerhead, theshowerhead may include no apertures 1007 about the interior portion 1014of the showerhead extending at least from the center point of theshowerhead to an area defined within at least 10% of the radial lengthof the showerhead. No apertures may additionally be included within aninterior portion 1014 of the showerhead extending from the center pointof the showerhead to an area defined within at least about 15%, 20%,25%, 30%, 35%, 40%, 45%, 50%, 60%, etc. or more.

Although illustrated as a single ring of apertures 1007, section 1016may include more than one ring of apertures 1007. Apertures 1007 may bedisposed at a variety of spacing intervals that may include continuousspacing between apertures 1007, as well as varied spacing orinconsistent spacing. If multiple rows of apertures 1007 are included,such as 2, 3, 4, 5, 6, 7, 8, 9, etc., or more rows of apertures, theapertures may be displaced between rows, or be in radial alignment froma radius of the showerhead extending out from a center point of theshowerhead 1000. In disclosed embodiments the exterior portion 1009 maybe of a thickness that is equal to, greater than, or less than thethickness of the interior portion 1014. Additionally, portion 1016 maybe of a thickness that is equal to, greater than, or less than thethickness of either or both of the exterior portion 1009 and interiorportion 1014. Materials included in each of portions 1009, 1014, and1016 may be similar or different from any of the other portions of theshowerhead 1000. For example, section 1016 may be of a materialdifferent from both exterior portion 1009 and interior portion 1014,which may include similar or different materials from one another. Forexample, exterior portion 1009 and interior portion 1014 may include ametal or conductive material, while section 1016 includes a dielectricmaterial that allows interior portion 1014 to be electrically isolatedfrom other portions of the system. In disclosed embodiments the exteriorportion 1009 and section 1016 may be of a similar non-conductingmaterial such as a dielectric material, while interior portion 1014 maybe made of a conductive material. Various other configurations as wouldbe understood are similarly encompassed by the technology.

In order to better understand and appreciate the technology described,reference is now made to FIG. 11 which is a flow chart of an etchprocess according to disclosed embodiments. It is understood that thetechnology can similarly be utilized for deposition processes inalternative arrangements. Prior to the first operation, a structure maybe formed in a patterned substrate. The structure may possess separateexposed regions of silicon, oxides, nitrides, metals including tungsten,copper, titanium, tantalum etc., or other components. Silicon may beamorphous, crystalline, or polycrystalline (in which case it is usuallyreferred to as polysilicon). Previous deposition and formation processesmay or may not have been performed in the same chamber. If performed ina different chamber, the substrate may be transferred to a system suchas that described above.

A first precursor such as an oxygen-containing precursor or ahydrogen-containing precursor may be flowed into a first plasma regionseparate from the substrate processing region at operation 1110. Theseparate plasma region may be referred to as a remote plasma regionherein and may be within a distinct module from the processing chamberor a compartment within the processing chamber. Generally speaking, ahydrogen or oxygen-containing precursor may be flowed into the firstplasma region, such as a first RPS unit as previously discussed, inwhich it is excited in a plasma, and the hydrogen or oxygen-containingprecursor may comprise at least one precursor selected from H₂, NH₃, O₂,O₃, N₂O, hydrocarbons, or the like. A flow of a second precursor such asnitrogen trifluoride, or a different fluorine-containing precursor, maybe introduced into a second remote plasma region at operation 1120 whereit is excited in a plasma. The first and second plasma systems may beoperated in any fashion as previously discussed, and in disclosedembodiments the hydrogen or oxygen-containing precursor and thefluorine-containing precursor may be flowed through the alternative RPSunits. Other sources of fluorine may be used to augment or replace thenitrogen trifluoride. In general, a fluorine-containing precursor may beflowed into the second remote plasma region and the fluorine-containingprecursor may include at least one precursor selected from the groupconsisting of atomic fluorine, diatomic fluorine, bromine trifluoride,chlorine trifluoride, nitrogen trifluoride, hydrogen fluoride,fluorinated hydrocarbons, sulfur hexafluoride, and xenon difluoride.Either or both of the first and second precursors may be included withcarrier precursors such as those previously discussed.

The plasma effluents formed in the remote plasma regions of the firstand second precursors may then be separately flowed into and thencombined in a mixing region of the chamber at operation 1130. The mixingregion may be located fluidly upstream of a processing region of thechamber in which a substrate, such as a patterned substrate, resides. Ifa chamber cleaning operation is being performed, a substrate may not belocated in the chamber during such operations. The gas flow ratios ofthe precursors may include a variety of flow ratios such as flow ratios(O or H:F) less than, greater than, or about 1:1000, 1:500, 1:250,1:100, 1:50, 1:25, 1:15, 1:10, 1:5, 1:1, 5:1, 10:1 15:1, 25:1, 50:1,100:1, 250:1, 500:1, 1000:1, etc. Regions of exposed tungsten, titaniumnitride, or other metals may also be present on the patterned substrateand may be referred to as exposed metallic regions. The precursors maybe delivered to the processing region and may react with the substratematerials to perform an etch operation, for example. The reactivechemical species may be removed from the substrate processing region andthen the substrate may be removed from the processing region.

The fluorine-containing precursor and/or the oxygen orhydrogen-containing precursor may further include one or more relativelyinert gases such as He, N₂, Ar, or the like. The inert gas can be usedto improve plasma stability and/or to carry liquid precursors to theremote plasma region. Flow rates and ratios of the different gases maybe used to control etch rates and etch selectivity. In an embodiment,the fluorine-containing gas may include NF₃ at a flow rate of betweenabout 1 sccm (standard cubic centimeters per minute) and 5000 sccm. Ahydrogen or oxygen-containing precursor may be included at a flow rateof between about 1 sccm and 5,000 sccm, and one or more carrier gases ata flow rate of between about 0 sccm and 3000 sccm, may be included witheither precursor stream. The atomic flow rates or ratio of O or H:F maybe kept high in disclosed embodiments to reduce or eliminate solidresidue formation on the substrate materials such as oxide. Theformation of solid residue consumes some silicon oxide which may reducethe silicon selectivity of the etch process. The atomic flow ratio of Oor H:F may be greater than or about five, twenty five (i.e. 25:1),greater than or about 30:1 or greater than or about 40:1 in embodimentsof the technology.

By maintaining the precursors fluidly separate, corrosion and otherinteraction with the RPS systems may be reduced or eliminated. Asdescribed above, the RPS units and distribution components including thegas distribution assembly may be made of materials selected based on theprecursors being delivered, and thus selected to prevent reactionbetween the ionized precursors and the equipment.

An ion suppressor may be used to filter ions from the plasma effluentsduring transit from the remote plasma region to the substrate processingregion in embodiments of the technology. The ion suppressor functions toreduce or eliminate ionically charged species traveling from the plasmageneration region to the substrate. Uncharged neutral and radicalspecies may pass through the openings in the ion suppressor to react atthe substrate. It should be noted that complete elimination of ionicallycharged species in the reaction region surrounding the substrate is notalways the desired goal. In many instances, ionic species are requiredto reach the substrate in order to perform the etch and/or depositionprocess. In these instances, the ion suppressor helps control theconcentration of ionic species in the reaction region at a level thatassists the process. In disclosed embodiments the upper plate of the gasdistribution assembly may include an ion suppressor.

The temperature of the substrate may be greater than 0° C. during theetch process. The substrate temperature may alternatively be greaterthan or about 20° C. and less than or about 300° C. At the high end ofthis substrate temperature range, the etch rate may drop. At the lowerend of this substrate temperature range, alternative components maybegin to etch and thus the selectivity may drop. In disclosedembodiments, the temperature of the substrate during the etchesdescribed herein may be greater than or about 30° C. while less than orabout 200° C. or greater than or about 40° C. while less than or about150° C. The substrate temperature may be below 100° C., below or about80° C., below or about 65° C. or below or about 50° C. in disclosedembodiments.

The process pressure may similarly be adjusted for various operations.The pressure within the substrate processing region may be below orabout 10 Torr, below or about 5 Torr, below or about 3 Torr, below orabout 2 Torr, below or about 1 Torr or below or about 750 mTorr indisclosed embodiments. In order to ensure adequate etch rate, thepressure may be below, above or about 0.02 Torr and range up to aboutatmospheric pressure, or about 760 Torr in embodiments of thetechnology. Additional examples, process parameters, and operationalsteps are included in previously incorporated application Ser. No.13/439,079 to the extent not inconsistent with the delivery mechanismsdescribed herein. The pressure may be modulated or determined based onthe plasma processing being performed. CCP plasma operations may beoperated at higher pressures than remote plasma processes. Inembodiments the operating pressures may be below about 20 Torr based onthe use of RPS units. However, in disclosed embodiments the RPS unit maybe sized or configured to operate at pressures above about 5 Torr, 10Torr, 20 Torr, 50 Torr, 100 Torr, up to about 760 Torr or above.

The RPS units exciting the precursors may be operated at any of theplasma powers as previously described. The RPS units may be operated atsimilar or different power levels in disclosed embodiments. For example,the first precursor excited in the first remote plasma unit may beexcited at a first plasma power level. The second precursor excited inthe second remote plasma unit may be excited at a second plasma powerlevel. The first and second plasma power levels may be similar ordifferent from one another with either plasma power level being greaterthan the other power level.

In the preceding description, for the purposes of explanation, numerousdetails have been set forth in order to provide an understanding ofvarious embodiments of the present technology. It will be apparent toone skilled in the art, however, that certain embodiments may bepracticed without some of these details, or with additional details.

Having disclosed several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of thedisclosed embodiments. Additionally, a number of well-known processesand elements have not been described in order to avoid unnecessarilyobscuring the present technology. Accordingly, the above descriptionshould not be taken as limiting the scope of the technology.

Where a range of values is provided, it is understood that eachintervening value, to the smallest fraction of the unit of the lowerlimit, unless the context clearly dictates otherwise, between the upperand lower limits of that range is also specifically disclosed. Anynarrower range between any stated values or unstated intervening valuesin a stated range and any other stated or intervening value in thatstated range is encompassed. The upper and lower limits of those smallerranges may independently be included or excluded in the range, and eachrange where either, neither, or both limits are included in the smallerranges is also encompassed within the technology, subject to anyspecifically excluded limit in the stated range. Where the stated rangeincludes one or both of the limits, ranges excluding either or both ofthose included limits are also included.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural references unless the context clearly dictatesotherwise. Thus, for example, reference to “an aperture” includes aplurality of such apertures, and reference to “the plate” includesreference to one or more plates and equivalents thereof known to thoseskilled in the art, and so forth.

Also, the words “comprise(s)”, “comprising”, “contain(s)”, “containing”,“include(s)”, and “including”, when used in this specification and inthe following claims, are intended to specify the presence of statedfeatures, integers, components, or steps, but they do not preclude thepresence or addition of one or more other features, integers,components, steps, acts, or groups.

What is claimed is:
 1. A system for semiconductor processing, the systemcomprising: a chamber configured to contain a semiconductor substrate ina processing region of the chamber, the chamber comprising a lid andsidewalls defining an internal volume of the chamber; a first remoteplasma unit fluidly coupled with a first access of the chamber definedthrough the lid and configured to deliver a first precursor into thechamber through the first access; a second remote plasma unit fluidlycoupled with a second access of the chamber separate from the firstaccess, the second access defined through the lid and configured todeliver a second precursor into the chamber through the second access,wherein the first and second accesses of the chamber provide access to amixing region in the internal volume of the chamber separate from andfluidly coupled with the processing region of the chamber, and whereinthe mixing region is configured to allow the first and second precursorsto interact with each other in the internal volume of the chamber andexternally from the processing region of the chamber; a showerheadpostioned within the chamber and at least partially defining the mixingregion from below, wherein the lid defines the mixing region from above;a faceplate positioned within the chamber between the showerhead and thesubstrate processing region of the chamber, wherein the faceplatedefines a plurality of apertures configured to allow the first precursorand the second percursor to flow from the mixing region towards theprocessing region; an ion suppressor positioned within the chamberbetween the faceplate and the substrate processing region of thechamber, wherein the faceplate is electrically coupled with an RFsource, wherein the ion suppressor is electrically grounded, and whereinthe chamber is configured to generate a capacitively-coupled plasmabetween the faceplate and ion suppressor operating as the electrodes ofthe capacitively-coupled plasma; and an annular dielectric insertpositioned between and contacting the faceplate and the ion suppressor,wherein the annular dielectric insert electrically isolates thefaceplate and ion suppressor from one another, wherein the showerhead,the faceplate, the ion suppressor, and the annular dielectric insert arecoaxially aligned along an axis of the chamber and configured to atleast partially define a flow passage along the axis of the chamber forthe first and second precursors to flow from the mixing region to theprocessing region.
 2. The system of claim 1, wherein the ion suppressoris configured to at least partially suppress the flow of ionic speciesdirected toward the processing region of the chamber.
 3. The system ofclaim 1, wherein the chamber further comprises a gas distributionassembly located within the chamber at a top portion of or above theprocessing region of the chamber and configured to deliver both thefirst and second precursors into the processing region of the chamber.4. The system of claim 3, wherein the gas distribution assemblycomprises an upper plate and a lower plate, wherein the upper and lowerplates are coupled with one another to define a volume between theplates, wherein the coupling of the plates provides first fluid channelsthrough the upper and lower plates and second fluid channels through thelower plate that are configured to provide fluid access from the volumethrough the lower plate, and wherein the first fluid channels arefluidly isolated from the volume between the plates and the second fluidchannels.
 5. The system of claim 4, wherein the volume is fluidlyaccessible through a side of the gas distribution assembly fluidlycoupled with a third access in the chamber separate from the first andsecond accesses of the chamber.
 6. The system of claim 3, wherein theion suppressor is directly coupled with and contacting the gasdistribution assembly at an exterior region of the ion suppressor. 7.The system of claim 1, wherein the first access and second access arecoupled with a top portion of the chamber.
 8. The system of claim 1,wherein the showerhead is configured to distribute the first and secondprecursors through the chamber.
 9. The system of claim 8, wherein adielectric spacer is positioned between the showerhead and the firstremote plasma unit and the second remote plasma unit, and wherein thedielectric spacer at least partially defines the mixing region.
 10. Thesystem of claim 1, wherein the first remote plasma unit comprises afirst material and the second remote plasma system comprises a secondmaterial.
 11. The system of claim 10, wherein the first material isselected based on the composition of the first precursor, and whereinthe second material is selected based on the composition of the secondprecursor.
 12. The system of claim 11, wherein the first material andsecond material are different materials.
 13. The system of claim 1,wherein the first remote plasma unit is configured to operate at a firstpower level that is selected based on the composition of the firstprecursor, and wherein the second remote plasma unit is configured tooperate at a second power level that is selected based on thecomposition of the second precursor.
 14. The system of claim 1, whereinthe faceplate, ion suppressor, and the annular dielectric insert arestacked with one another to at least partially define sidewalls of thechamber.
 15. The system of claim 1, wherein the ion suppressor includesa plurality of rings of apertures, wherein each ring is hexagonallyshaped, and wherein each of the apertures of each ring is arranged at anequal distance from each adjacent apertures.
 16. The system of claim 1,wherein the faceplate includes a plurality of apertures each configuredto facilitate the flow of at least a portion of ions from the firstprecursor or the second precursor through the faceplate.
 17. The systemof claim 1, wherein the faceplate includes a plurality of apertures eachconfigured with a tapered portion extending outward toward theprocessing region, and wherein the ion suppressor includes a pluralityof apertures each configured with a tapered portion extending outwardaway from the processing region.
 18. The system of claim 1, wherein thefaceplate and the ion suppressor are configured to generate thecapacitively-coupled plasma at a power level below or about 1 kW suchthat concentrations of radical species entering into the processingregion are similar to concentrations of radical species entering intothe mixing region from the first remote plasma unit and the secondremote plasma unit.
 19. The system of claim 1, wherein the showerheadincludes a first plurality of apertures, wherein the faceplate includesa second plurality apertures, wherein the ion suppressor includes athird plurality of apertures, and wherein a density of the secondplurality of apertures is less than a density of the first plurality ofapertures and is less than a density of the third plurality ofapertures.
 20. The system of claim 1, wherein the coupling between thefirst remote plasma unit and the chamber and the coupling between thesecond remote plasma and the chamber are respectively configured suchthat a flow path for the first precursor to travel from the first remoteplasma unit to the mixing region of the chamber is greater than a flowpath for the second precursor to travel from the second remote plasmaunit to the mixing region of the chamber, and wherein the flow paths aredetermined based at least in part on respective recombination rates ofradicals from the first precursor and the second precursor.
 21. A systemfor semiconductor processing, the system comprising: a chamberconfigured to contain a semiconductor substrate in a processing regionof the chamber, the chamber comprising a lid and sidewalls defining aninternal volume of the chamber; a first remote plasma unit fluidlycoupled with a first access of the chamber defined through the lid andconfigured to deliver a first precursor into the chamber through thefirst access; a second remote plasma unit fluidly coupled with a secondaccess of the chamber separate from the first access, the second accessdefined through the lid and configured to deliver a second precursorinto the chamber through the second access, wherein the first and secondaccesses of the chamber provide access to a mixing region in theinternal volume of the chamber separate from and fluidly coupled withthe processing region of the chamber, and wherein the mixing region isconfigured to allow the first and second precursors to interact witheach other in the internal volume of the chamber and externally from theprocessing region of the chamber; a showerhead positioned within thechamber to at least partially define the mixing region from below,wherein the lid defines the mixing region from above; an annular insertpositioned adjacent the showerhead and defining an exterior of themixing region; an ion suppressor positioned within the chamber betweenthe showerhead and the substrate processing region of the chamber,wherein the ion suppressor comprises a plate defining apertures, andwherein the ion suppressor is configured to operate as an electricallygrounded electrode for a capacitively-coupled plasma formable within thechamber; an annular dielectric insert positioned between the ionsuppressor and the showerhead, wherein the annular dielectric insert isin contact with the ion suppressor; and a gas distribution assemblypositioned between the ion suppressor and the processing region of thechamber, wherein the gas distribution assembly is in direct contact withthe ion suppressor.
 22. The system of claim 21, wherein the showerhead,the ion suppressor, the annular insert, the annular dielectric insert,and the gas distribution assembly are in a stacked arrangement, and eachat least partially define sidewalls of the chamber.
 23. A system forsemiconductor processing, the system comprising: a chamber configured tocontain a semiconductor substrate in a processing region of the chamber,the chamber comprising a lid and sidewalls defining an internal volumeof the chamber; a first remote plasma unit fluidly coupled with a firstaccess of the chamber defined through the lid and configured to delivera first precursor into a mixing region of in the internal volume of thechamber, wherein the mixing region is separate from and fluidly coupledwith the processing region of the chamber; a second remote plasma unitfluidly coupled with a second access of the chamber separate from thefirst access, the second access defined through the lid and configuredto deliver a second precursor into the mixing region in the internalvolume of the chamber through the second access, wherein the mixingregion is configured to allow the first and second precursors tointeract with each other in the internal volume of the chamber andexternally from the processing region of the chamber; a first annularinsert positioned downstream of and contacting the lid and configured toat least partially define the sidewalls; a showerhead positioneddownstream of and contacting the first annular insert, wherein theshowerhead defines a plurality of apertures, and wherein the lid, thefirst annular insert, and the showerhead are configured to collectivelydefine the mixing region; a second annular insert positioned downstreamof and contacting the showerhead and configured to at least partiallydefine the sidewalls; a faceplate positioned downstream of theshowerhead and spaced apart from the showerhead by the second annularinsert, wherein the faceplate defines a plurality of apertures; a thirdannular insert positioned downstream of and contacting the faceplate andconfigured to at least partially define the sidewalls; an ion suppressorpositioned downstream of and contacting the third annular insert,wherein the ion suppressor defines a plurality of apertures, wherein thefaceplate is electrically coupled with an RF source, wherein the ionsuppressor is electrically grounded, wherein the third annular insert isconfigured to electrically isolate the faceplate and ion suppressor fromone another, wherein the faceplate, the ion suppressor, and the thirdannular insert are configured to define a chamber plasma region, whereinthe mixing region, the chamber plasma region, and the processing regionare arranged along an axis of the chamber, wherein the faceplate and theion suppressor are configured to operate as electrodes for generating acapacitively-coupled plasma within the chamber plasma region, whereineach of the plurality of apertures of the faceplate is configured with atapered portion extending outward toward the chamber plasma region, andwherein each of the plurality of apertures of the ion suppressor isconfigured with a tapered portion extending outward toward the chamberplasma region; a gas distribution assembly positioned downsteam of andcontacting the ion suppressor, wherein the gas distribution assembly isconfigured to at least partially define the processing region, whereinthe gas distribution assembly further includes an annular bodyconfigured to at least partially define the sidewalls, and wherein theshowerhead, the second annular insert, the faceplate, the third annularinsert, and the ion suppressor collectively define a flow passage alongthe axis of the chamber for the first and second precursors to flow fromthe mixing region to the processing region; and a pedestal configured tosupport the semicondcutor substrate in the processing region, whereinthe showerhead, the faceplate, the ion suppressor, and the gasdistribution assembly, and the substrate support are coaxially alignedalong the axis of the chamber.